I have a 2D design for some packaging. I've placed a JPG of this design into the Symbols panel to mock up as 3D. I've drawn the path/shape (I've tried closed shape & open path), to turn into the 3D shape. (I've tried stroke, no stroke, fill, no fill) But when selecting the image when in the 3D and Materials panel to place the design onto the image doesn't show up on the mock up. What am I doing wrong?